Sea Levels Rising

http://www.nytimes.com/2014/01/14/science/earth/grappling-with-sea-level-rise-sooner-not-later.html?ref=science&_r=0

Much of the population and economy of the country is concentrated on the East Coast, which the accumulating scientific evidence suggests will be a global hot spot for a rising sea level over the coming century. The detective work has required scientists to grapple with the influence of ancient ice sheets, the meaning of islands that are sinking in the Chesapeake Bay, and even the effect of a giant meteor that slammed into the earth. The work starts with the tides. Because of their importance to navigation, they have been measured for the better part of two centuries. While the record is not perfect, scientists say it leaves no doubt that the world’s oceans are rising. The best calculation suggests that from 1880 to 2009, the global average sea level rose a little over eight inches. That may not sound like much, but scientists say even the smallest increase causes the seawater to eat away more aggressively at the shoreline in calm weather, and leads to higher tidal surges during storms. The sea-level rise of decades past thus explains why coastal towns nearly everywhere are having to spend billions of dollars fighting erosion. The evidence suggests that the sea-level rise has probably accelerated, to about a foot a century, and scientists think it will accelerate still more with the continued emission of large amounts of greenhouse gases into the air. The gases heat the planet and cause land ice to melt into the sea. The official stance of the world’s climate scientists is that the global sea level could rise as much as three feet by the end of this century, if emissions continue at a rapid pace. But some scientific evidence supports even higher numbers, five feet and beyond in the worst case.